Heat the milk over a medium high heat and remove from the heat just before it boils, add the vanilla seeds, stir well and allow to cool a little
As the milk is cooling, place the sugar to the egg yolks into a clean bowl and whisk vigorously until well combined. The mixture will become paler and increase in size after a couple of minutes
While still whisking, pour over the warm milk slowly until combined
Return the mixture into the pan on a low medium heat and keep stirring for 2-4 minutes until the mixture thickens a little. To test the thickening, dip a spoon into the custard and run your finger down the back. If it leaves a clean line and holds its shape somewhat, it is done
Remove from the heat and pour into a cool bowl. Allow it to cool to room temperature or place it in an ice bath to cool quicker. (See recipe notes) Stir frequently during the cooling process
Once cooled, if using an ice cream maker, follow the user guidelines for best results. Once churned, place in a resealable, freezer-safe container and store in the freezer
If making this recipe manually, keep the cooled mixture in the ice bath and continue to whisk for 3-5 additional minutes depending on whether you're mixing manually or with an electric mix. Once this is done, scrape into your resealable, freezer-safe container. Place in the freezer for ½ hour. After ½ hour, remove and stir well using a spatula or spoon, making sure to scrape down the sides of the container and place back in the freezer. Repeat every ½ hour for the next 2 hours. After this, repeat the stirring every hour until the desired consistency and smoothness is reached. This repeated stirring discourages the formation of ice crystals and leaves you with a delicious smooth ice cream